package com.jy.oms.framework.util;

import org.springframework.aop.framework.AdvisedSupport;
import org.springframework.aop.framework.AopProxy;
import org.springframework.aop.support.AopUtils;
import org.springframework.util.ClassUtils;

import java.lang.reflect.Field;
import java.lang.reflect.Proxy;

/**
 * 获得spring代理对象的原对象
 *
 * @author liuquan
 */
public class AopTargetUtils {

    /**
     * 获取 目标对象
     *
     * @param proxy 代理对象
     */
    public static Object getTarget(Object proxy) throws Exception {
        if (AopUtils.isAopProxy(proxy)) {
            if (AopUtils.isJdkDynamicProxy(proxy)) {
                return getSpringJdkProxyTarget(proxy);
            } else {
                return getSpringCglibTarget(proxy);
            }
        } else {
            if (Proxy.isProxyClass(proxy.getClass())) {
                return getJdkProxyTarget(proxy);
            } else if (ClassUtils.isCglibProxy(proxy.getClass())) {
                return getCglibTarget(proxy);
            } else {
                return proxy;
            }
        }
    }

    private static Object getSpringCglibTarget(Object proxy) throws Exception {
        Field h = proxy.getClass().getDeclaredField("CGLIB$CALLBACK_0");
        h.setAccessible(true);
        Object dynamicAdvisedInterceptor = h.get(proxy);

        Field advised = dynamicAdvisedInterceptor.getClass().getDeclaredField("advised");
        advised.setAccessible(true);

        return ((AdvisedSupport) advised.get(dynamicAdvisedInterceptor)).getTargetSource().getTarget();
    }

    private static Object getSpringJdkProxyTarget(Object proxy) throws Exception {
        Field h = proxy.getClass().getSuperclass().getDeclaredField("h");
        h.setAccessible(true);
        AopProxy aopProxy = (AopProxy) h.get(proxy);

        Field advised = aopProxy.getClass().getDeclaredField("advised");
        advised.setAccessible(true);

        return ((AdvisedSupport) advised.get(aopProxy)).getTargetSource().getTarget();
    }

    private static Object getCglibTarget(Object proxy) throws Exception {
        Field h = proxy.getClass().getDeclaredField("CGLIB$CALLBACK_0");
        h.setAccessible(true);

        //这里并不是真正的原始对象
        return h.get(proxy);
    }

    private static Object getJdkProxyTarget(Object proxy) throws Exception {
        Field h = proxy.getClass().getSuperclass().getDeclaredField("h");
        h.setAccessible(true);

        //这里并不是真正的原始对象
        return h.get(proxy);
    }
}

